Wood-working machines for the processing of long specimens, such as beams, boards, panels, or the like usually have one or more processing units, a work support, and a transporting device for the movement and positioning of the workpieces lying on the workpiece support, relative to the processing unit in a linear axis. The motion of the workpiece for the precise positioning of the workpiece with the known wood-working machines is detected, for example, by a measuring roller located in the feed device of the workpiece, in front of the processing unit.